Catheters, particularly intravascular (IV) catheters, are used for infusing fluid, such as normal saline solution, various medicaments and total parenteral nutrition, into a patient, withdrawing blood from a patient or monitoring various parameters of the patient's vascular system. Peripheral IV catheters tend to be relatively short, and typically are on the order of about two inches or less in length.
The most common type of IV catheter is an over-the-needle peripheral IV catheter.
As its name implies, an over-the-needle catheter is mounted over an introducer needle having a sharp distal tip. At least the distal portion of the catheter tightly engages the outer surface of the needle to prevent peelback of the catheter and thus facilitates insertion of the catheter into the blood vessel. The catheter and the introducer needle are assembled so that the distal tip of the introducer needle extends beyond the distal tip of the catheter with the bevel of the needle facing up away from the patient's skin.
The catheter and introducer needle assembly is inserted at a shallow angle through the patient's skin into a blood vessel. There are many techniques for inserting such a catheter and introducer needle assembly into a patient. In one insertion technique, the introducer needle and catheter are inserted completely into the blood vessel together. In another technique, the introducer needle is partially withdrawn into the catheter after the initial insertion into the blood vessel. The catheter is then threaded over the needle and inserted completely into the blood vessel.
The clinical utilization of a pointed hollow needle mounted inside a flexible catheter tube is well known in the medical art for the introduction of a catheter. In such a medical instrument, the catheter tube is positioned tightly around the needle in such a way as to allow the needle to slide and telescope along the length of the catheter tube. Before use, the tip of the needle is protruding slightly through the opening of the catheter tube to allow facile penetration through the skin. Upon puncturing of the skin and introduction of the needle, the distal end of the catheter tube is simultaneously brought into place inside the desired target body cavity of the patient, such as the inside of a blood vessel, for example a vein. The needle has then done its duty in assisting the introduction of the catheter and is withdrawn by being pulled backwards through the catheter. Upon release of the needle, the catheter is set in its intended working mode extending over a lengthier period of time and including, for example, periodical administration or infusion of fluids or medications in liquid form, the collection of blood samples and the like.
With regard to over-the-needle catheters, there are mainly two major alternatives. The first one, the open IV catheter system, such as the Venflon®-type, comprises luer through which the needle is withdrawn after insertion of the catheter into the blood vessel, which is connectable to blood withdrawal or infusion means, as well as an optional port for the same purpose. The second one, the closed IV catheter system, such as the Nexiva™-type, comprises a septum in an catheter hub through which the needle is withdrawn after insertion of the catheter into the blood vessel, closing off the “needle channel” from the environment, and instead has an extension tube extending laterally from the catheter hub, wherein the extension tube is in fluid communication with the catheter hub cavity and the lumen of the catheter positioned in the blood vessel. These two alternatives are accompanied with different problems and benefits.
In recent years, there has been great concern over the contamination of clinicians with a patient's blood and a recognition that “blood contaminated sharps” must be disposed to avoid an accidental needle stick. This concern has arisen because of the advent of currently incurable and fatal diseases, such as Acquired Immunosuppressive Deficiency Syndrome (“AIDS”), hepatitis, etc., which can be transmitted by the exchange of body fluids from an infected person to another person.
As a result of the problem of accidental needlesticks by “blood contaminated sharps”, various needle shields have been developed for use in conjunction with intravenous catheters. Due to the difference in configuration between an open and a closed IV catheter system, different needle shields and configurations have been introduced with regard to the two alternatives.
With regard to closed IV catheter systems, the catheter hub has to be of a material compatible with adhesion of the extension tubing. Such a material is for example polycarbonate, which is a hard and brittle polymer with a high impact strength. Additionally, the septum in the catheter hub takes up the proximal part of the catheter hub.
The present disclosure discloses a closed IV catheter system, wherein a needle shield assembly is positioned proximally of the catheter hub and distally of the needle hub, and wherein the needle shield assembly cooperates with the catheter hub on the outer circumferential and peripheral surface of the catheter hub. This means that the needle shield adds additional length and width to the closed IV catheter system. Additionally, the needle shield assembly could be reached and perhaps released unintentionally from the catheter hub, and not as envisioned only by withdrawal of the needle hub.
Hence, a needle shield assembly with improved volume occupying characteristics, as well as decreased risk of undue needle shield assembly release with regard to a closed IV catheter system, is desired.